In the art, a switching process (network selection and traffic steering) in which a waiting destination or a connection destination is switched between the wireless LAN and the mobile communication network when at least a part of a coverage area of a wireless LAN and a coverage area of the mobile communication network represented by LTE (Long Term Evolution) overlap each other is proposed. Specifically, the switching process is performed depending on whether first information of a mobile communication network side and second information of a wireless LAN side satisfy a first condition and a second condition, respectively.
Examples of the first information of the mobile communication network side include: a measurement result (RSRPmeas) of the level of a received signal (reference signal received power [RSRP]); and a measurement result (RSRQmeas) of the quality of a received signal (reference signal received quality [RSRQ]). Examples of the second information of the wireless LAN side include: a channel utilization value of the wireless LAN; a backhaul value of the wireless LAN; and a signal strength of a received signal (received signal strength indicator [RSSI]).
A radio base station provided in the mobile communication network informs a radio terminal of determination parameters to determine whether a switching process through which a waiting destination or a connection destination is switched between the mobile communication network and the wireless LAN is performed. There are a dedicated parameter of which the radio terminal dedicatedly informed and a broadcast parameter broadcasted to the radio terminal, as the determine parameters.